The present invention relates to a method for manufacturing a magnetic transducer head and more particularly to a method including a deposition process for non-magnetic material to fill grooves defining a track width of the head.
Recently, a bonding method utilizing low-temperature metal diffusion has been developed, and efforts have been made to apply the bonding method primarily to bonding magnetic core members together to form a gap in manufacturing a magnetic head.
The use of low-temperature metal diffusion eliminates a high-temperature heating process such as the fusion of glass, and makes possible the utilization of amorphous magnetic alloys having low heat resistance for forming a so-called metal-in-gap type magnetic head.
When low temperature metal diffusion is used for bonding magnetic core members to form a gap, filling track width regulating grooves with a nonmagnetic material is a problem.
In an ordinary video head, a core (a portion of a magnetic head that is brought into sliding contact with a magnetic recording medium) is formed, in general, in a width greater than the track width in view of abrasion resistance, and the magnetic core is provided with grooves for regulating the track width. When the magnetic core members are bonded together by the fusion of glass to form a gap, the grooves are filled with the glass. When the magnetic core members are bonded together by low-temperature metal diffusion, the grooves, form void spaces. Such void spaces may possibly damage a magnetic tape or may possibly spoil the contact between the magnetic head and the magnetic tape.
Such a problem may be solved by filling up the void spaces with glass after bonding together the magnetic core members to form a magnetic core, which however, requires heating the magnetic core to a temperature which is high enough to melt flow a glass. Therefore, it is impossible to use an amorphous alloy having a low temperature of crystallization if a reliable glass having a high melting point is used for filling up the void spaces, and the advantage of low-temperature metal diffusion is nullified.
The use of a glass having a low melting point may be effective to make the most of the advantage of low-temperature metal diffusion. However, such a glass is not satisfactory in reliability and will cause partial abrasion. Even if a glass having a low melting point is employed, the magnetic core needs unavoidably to be heated at a comparatively high temperature, and only limited magnetic metals can be used.
Filling the track width regulating grooves with glass requiring a high-temperature heating process imposes many restrictions on the selection of materials for a magnetic head, and hence it is impossible to make the most of the advantage of lo temperature metal diffusion in combination with filling the track width regulating grooves with glass. Furthermore, it is possible that the use of fused glass for filling up the voids entails partial abrasion due to the poor abrasion resistance of the glass, regardless of whether or not the magnetic core members are bonded together by low-temperature metal diffusion.